Problem is that it doesn't work at all in MOP. I don't know much about coding, if I knew what is wrong exactly, then maybe i could change it myself, but there is no LUA errors, so i have no idea how to fix this addon, if anyone can give me some guidance, on how to fix this addon for MOP i would be rly greatful.

Or maybe someone knows how to create a simple Nameplates addon for MOP, from the scratch, I need 2 functions:

-Default Nameplates with Smooth Texture
-Health Percentages display in the middle of nameplate.

In your code, you'd put something similar inside the "SkinPlates" function. In fact, you're already using the first line I posted in your own code. Those lines simply get references to the various parts of the nameplate, and then you would need to write more code to actually modify them (eg. by moving them, changing the font, etc.).

Alternatively, you could just use a nameplate addon that's actually still maintained, or a more customizable nameplate addon that lets you change textures and fonts in-game.

So this should be done like this?, couse ive just tested it, but it still doesnt display hp% ;(

Nameplates don't include health text by default. You have to create a font string and update it each time the health changes. Look at the code in the addon I linked in my last post; you should be able to mostly just copy and paste. Look for sections of code that mention "health".